1. Technical Field
This disclosure relates to a press molding machine for a disk-shaped member and a press molding method.
2. Related Art
JP-A-2013-000229 discloses the reclining seat belonging to the related art. This seat includes the reclining mechanism, which is disposed between the seat cushion side frame and the seat back side frame. This reclining mechanism includes the disk-shaped base plate, the disk-shaped ratchet plate, the rotation center shaft, the three lock members, the cam, and the lock spring. The disk-shaped base plate is secured to the seat cushion side frame. The disk-shaped ratchet plate is secured to the seat back side frame and has annular internal teeth on the inner peripheral surface. The rotation center shaft is inserted into the center through-hole (the shaft support hole) of the base plate and the ratchet plate. The lock members are supported by the base plate so as to be relatively movable in the radial direction of the rotation center shaft. The cam rotates in conjunction with the rotation center shaft. The lock spring rotatably biases the cam.
The base plate and the ratchet plate are made of metal. Generally, these plates are manufactured by performing a progressive press on a base material formed of a metal plate using a press molding machine.
For example, to mold the ratchet plate by the progressive press using the press molding machine, a plurality of molding dies are aligned in a conveying direction (a horizontal direction) of the base material (the workpiece) to set the molding dies in the press molding machine. These molding dies are necessary by the number of process operations (presswork). That is, for example, a drilling molding die, a concavo-convex shape forming molding die, an outer shape cutting molding die, an internal teeth forming molding die, and the like are necessary. The drilling molding die drills a center through-hole (a shaft support hole) on the base material. The concavo-convex shape forming molding die molds concavo-convex shapes formed on the front surface and the back surface of the base material. The outer shape cutting molding die cuts out a disk having an outer shape (a circular shape) identical to the ratchet plate from the base material. The internal teeth forming molding die forms internal teeth on the inner peripheral surface of the disk.
The press molding machine includes one driving unit. To this driving unit, mold support unit is coupled so as to be vertically movable. This mold support unit supports the respective molding dies.
When the base material is supplied to the press molding machine where these molding dies are set, the conveying unit, which is disposed in the press molding machine, moves the base material in one direction (the horizontal direction) at predetermined pitches. In each execution of the conveying operation, the respective molding dies simultaneously perform a press molding operation (vertical movement) on different sites of the base material (the plurality of sites separated from one another by the pitches).
Accordingly, when the base material is conveyed by the predetermined number of pitches (the number of pitches identical to a number of the types of molding dies), molding (processing) to the predetermined sites on the base material with the drilling molding die, the concavo-convex shape forming molding die, the outer shape cutting molding die, and the internal teeth forming molding die is all completed. These sites become the completed product of the ratchet plate (the ratchet plate includes the center through-hole, the plurality of concavo-convex portions, and internal teeth. The center through-hole is drilled with the drilling molding die. The concavo-convex portions are formed with the concavo-convex shape forming molding die. The concavo-convex portions are positioned on the outer periphery side of the center through-hole. The internal teeth are disposed on the inner peripheral portion of the disk and are formed with the internal teeth forming molding die. The ratchet plate is a processed product cut out as the disk-shaped member at a site positioned on the outer periphery side of the concavo-convex portion with the outer shape cutting molding die).
Repeating these operations sequentially manufactures (press-molds) a plurality of (a large number of) ratchet plates from the base material.
Setting the various molding dies for base plate molding to the press molding machine allows manufacturing the plurality of base plates from the base material formed of a metal plate by the manner (the progressive press) similar to the manner for the ratchet plate.